Dahlia plant named ‘HS Romeo’

ABSTRACT

A new and distinct cultivar of  Dahlia  plant named ‘HS Romeo’, characterized by its upright and outwardly spreading plant habit; freely branching growth habit; dark-colored foliage; early and freely flowering habit; daisy inflorescence form; large inflorescences with dark red purple-colored ray florets; and good postproduction longevity and garden performance.

Botanical designation: Dahlia hybrida.

Cultivar denomination: ‘HS Romeo’.

CROSS-REFERENCE TO RELATED APPLICATIONS

Dahlia Plant Named ‘HS First Love’; Aad W.M. Verwer, Applicant; disclosed in U.S. Plant Pat. No. 16,984.

BACKGROUND OF THE INVENTION

The present Invention relates to a new and distinct cultivar of Dahlia plant, botanically known as Dahlia hybrida and hereinafter referred to by the name ‘HS Romeo’.

The new Dahlia is a product of a planned breeding program conducted by the Inventor in Lisse, The Netherlands. The objective of the breeding program is to create new compact potted Dahlia cultivars that have a freely branching growth habit, dark green-colored foliage, early and freely flowering habit, daisy inflorescence form, attractive ray floret coloration, inflorescences that are not persistent, and good postproduction longevity and garden performance.

The new Dahlia originated from a chance open-pollination in 1999 of a proprietary selection of Dahlia hybrida identified as code number Vd1-216, not patented, as the female, or seed, parent with an unknown selection of Dahlia hybrida as the male, or pollen, parent. The new Dahlia was discovered and selected by the Inventor as a single flowering plant within the progeny of the stated open-pollination grown in a controlled environment in Lisse, The Netherlands in 2000.

Asexual reproduction of the new Dahlia by cuttings was first conducted in Lisse, The Netherlands during the spring of 2001. Asexual reproduction by cuttings has shown that the unique features of this new Dahlia are stable and reproduced true to type in successive generations.

SUMMARY OF THE INVENTION

The cultivar HS Romeo has not been observed under all possible environmental conditions. The phenotype may vary somewhat with variations in environment such as temperature and light intensity without, however, any variance in genotype.

The following traits have been repeatedly observed and are determined to be the unique characteristics of ‘HS Romeo’. These characteristics in combination distinguish ‘HS Romeo’ as a new and distinct Dahlia cultivar:

-   -   1. Upright and outwardly spreading plant habit.     -   2. Freely branching growth habit.     -   3. Dark-colored foliage.     -   4. Early and freely flowering habit.     -   5. Daisy inflorescence form.     -   6. Large inflorescences with dark red purple-colored ray         florets.     -   7. Good postproduction longevity and garden performance.

Plants of the new Dahlia differ primarily from plants of the female parent selection in the following characteristics:

-   -   1. Plants of the new Dahlia are more compact than plants of the         female parent selection.     -   2. Plants of the new Dahlia have shorter internodes than plants         of the female parent selection.     -   3. Plants of the new Dahlia and the female parent selection         differ in ray floret coloration.

Plants of the new Dahlia can be compared to the Dahlia cultivar HS First Love, disclosed in U.S. Plant Pat. No. 16,984. Plants of the new Dahlia differ from plants of the cultivar HS First Love primarily in ray floret coloration.

Plants of the new Dahlia can also be compared to plants of the cultivar Sunshine, not patented. In side-by-side comparisons conducted in Lisse, The Netherlands, plants of the new Dahlia differed from plants of the cultivar Sunshine in the following characteristics:

-   -   1. Plants of the new Dahlia were smaller than plants of the         cultivar Sunshine.     -   2. Plants of the new Dahlia had larger leaves than plants of the         cultivar Sunshine.     -   3. Plants of the new Dahlia were more freely flowering than         plants of the cultivar Sunshine.     -   4. Plants of the new Dahlia had slightly smaller inflorescences         than plants of the cultivar Sunshine.     -   5. Ray florets of plants of the new Dahlia were dark red purple         in color while ray florets of plants of the cultivar Sunshine         were yellow orange in color.     -   6. Plants of the new Dahlia had more and larger disc florets per         inflorescence than plants of the cultivar Sunshine.

BRIEF DESCRIPTION OF THE PHOTOGRAPH

The accompanying colored photograph illustrates the overall appearance of the new Dahlia showing the colors as true as it is reasonably possible to obtain in colored reproductions of this type. Colors in the photograph may differ from the color values cited in the detailed botanical description which accurately describe the colors of the new Dahlia. The photograph comprises a side perspective view of a typical flowering plant of ‘HS Romeo’.

DETAILED BOTANICAL DESCRIPTION

In the following description, color references are made to The Royal Horticultural Society Colour Chart, 1995 Edition, except where general terms of ordinary dictionary significance are used. The aforementioned photograph and the following observations and measurements describe plants grown and flowered during the summer and early autumn in Lisse, The Netherlands, in an outdoor nursery and under conditions which approximate those generally used in commercial production. During the production of the plants, day temperatures ranged between 15 and 30° C. and night temperatures ranged between 10 and 20° C. Plants were pinched one time about three to four weeks after planting rooted cuttings. Plants were about four months old when the photographs and the description were taken.

-   Botanical classification: Dahlia hybrida cultivar HS Romeo. -   Parentage:     -   -   Female, or seed, parent.—Proprietary selection of Dahlia             hybrida identified as code number Vd1-216, not patented.         -   Male, or pollen, parent.—Unknown selection of Dahlia             hybrida, not patented. -   Propagation:     -   -   Type.—By vegetative cuttings.         -   Time to initiate roots.—Summer: About three days at 17° C.             Winter: About four days at 17° C.         -   Time to produce a rooted young plant.—Summer: About 12 days             at 17° C. Winter: About 15 days at 17° C.         -   Root description.—Fine, fibrous; older roots, fleshy.         -   Rooting habit.—Freely branching; dense.         -   Tuber description.—Tuber development has not been observed. -   Plant description:     -   -   Appearance.—Perennial daisy-type potted Dahlia. Upright and             outwardly spreading plant habit; inverted triangle. Freely             branching habit, about six lateral branches; dense and full             plants. Moderately vigorous growth habit.         -   Plant height.—About 50 cm.         -   Plant diameter.—About 30 cm.         -   Lateral branch description.—Length: About 30 to 40 cm.             Diameter: About 4 mm. Internode length: About 5 to 15 cm.             Strength: Strong. Texture: Glabrous, smooth. Color: 187A.         -   Foliage description.—Arrangement: Leaves opposite; leaves             may be single or compound with three or five leaflets.             Shape: Ovate. Apex: Acuminate. Base: Attenuate. Margin:             Serrate; sinuses divergent. Length: Single leaves: About             10 cm. Compound leaves with three leaflets: About 15 cm.             Compound leaves with five leaflets: About 19 cm. Width:             Single leaves: About 5 cm. Compound leaves with three             leaflets: About 15 cm. Compound leaves with five leaflets:             About 18 cm. Venation pattern: Pinnate. Texture, upper and             lower surfaces: Smooth, glabrous. Color: Developing foliage,             upper surface: 137A. Developing foliage, lower surface:             148B. Fully expanded foliage, upper surface: 137A overlain             with 187A. Fully expanded foliage, lower surface: 148B.             Venation, upper surface: 187B. Venation, lower surface: 137B             overlain with 187C. Petiole length: Single leaves: About             4 cm. Compound leaves with three leaflets: About 4 cm.             Compound leaves with five leaflets: About 4 cm. Petiole             diameter: Single leaves: About 8 mm. Compound leaves with             three leaflets: About 8 mm. Compound leaves with five             leaflets: About 8 mm. Petiole color, upper surface: 59A.             Petiole color, lower surface: 144A overlain with 59B. -   Inflorescence description:     -   -   Appearance.—Daisy inflorescence form; inflorescences rotate.             Inflorescences borne on terminals, arising from leaf axils,             positioned above the foliage. Ray and disc florets develop             acropetally on the receptacle. Inflorescences not fragrant.             Inflorescences persistent.         -   Flowering response.—Flowering recurrent to continuous during             the summer and autumn in The Netherlands. Early flowering             habit, plants start flowering about 60 days after planting.         -   Postproduction longevity.—On the plant, inflorescences             maintain good color and substance for about 18 days in an             outdoor environment. As cut flowers, inflorescences maintain             good color and substance for about five days in an indoor             environment.         -   Quantity of inflorescences per flowering stem.—About 50             inflorescences and inflorescence buds per plant.         -   Inflorescence size.—Diameter: About 9 cm. Depth (height):             About 2 cm. Diameter of disc: About 2.2 cm. Receptacle             diameter: About 1.6 cm. Receptacle height: About 1.1 cm.         -   Inflorescence buds.—Length: About 1.5 cm. Diameter: About             1.8 cm. Shape: Oblate. Color: Towards the apex, 178A;             towards the base, 146A.         -   Ray florets.—Number of ray florets per inflorescence: About             eight in a single whorl. Length, fully developed: About             4.3 cm. Width, fully developed: About 2.5 cm. Orientation:             Initially upright, eventually close to perpendicular to the             peduncle; mostly flat. Shape: Ovate. Apex: Mucronate. Base:             Attenuate. Margin: Entire. Texture, upper and lower             surfaces: Smooth, glabrous; velvety. Venation pattern:             Parallel. Color: When opening, upper surface: 59A. When             opening, lower surface: 59A; along the veins, 72A. Fully             opened, upper surface: 60A. Fully opened, lower surface:             60A; along the veins, 72A.         -   Disc florets.—Number of disc florets per inflorescence:             About 100. Length: About 1 cm. Width, at the apex: About             1 mm. Width, at the base: About 0.2 mm. Shape: Tubular,             elongated. Apex: Pentafid. Base: Attenuate. Color: Immature:             187A. Mature: Apex: 187A. Mid-section: 178A. Base: 150C.         -   Phyllaries.—Quantity/arrangement: One whorl with about five             or six phyllaries per inflorescence. Length: About 1.5 cm.             Width: About 1.2 cm. Shape: Ovate. Apex: Rounded. Base:             Attenuate. Margin: Entire. Texture, upper and lower             surfaces: Smooth, glabrous; leathery. Color, upper surface:             187A. Color, lower surface: 200A.         -   Peduncles.—Length, terminal peduncle: About 10 cm. Length,             fourth peduncle: About 15 cm. Diameter: About 4 mm. Angle:             Erect to about 30° from vertical. Strength: Strong. Texture:             Glabrous, smooth. Color: Darker than 187A.         -   Reproductive organs.—Androecium: Present on disc florets             only. Stamen quantity: About five per floret. Anther shape:             Linear. Anther length: About 3 mm. Anther color: 16C. Pollen             amount: Moderate. Pollen color: 15A. Gynoecium: Present on             ray and disc florets. Pistil quantity: One per floret.             Pistil length: About 5 mm. Stigma shape: Lanceolate. Stigma             color: 12A. Style length: About 4 mm. Style color: 150C.             Ovary color: 8B.         -   Seeds.—Length: About 6 mm. Diameter: About 1 mm. Color:             200A. -   Disease/pest resistance: Resistance to pathogens and pests common to     Dahlias has not been observed on plants grown under commercial     greenhouse or outdoor conditions. -   Weather tolerance: Plants of the new Dahlia have been observed to be     very tolerant to wind, rain and full sun conditions. Plants of the     new Dahlia have been observed to tolerate temperatures from 0 to 40°     C. 

1. A new and distinct cultivar of Dahlia plant named ‘HS Romeo’, as illustrated and described. 